Figure 2.

Example Beacon screening data for candidate D59047-11955. Anti-mouse IgG capture beads (brightfield image) were imported into channels above the pens. Antibody secretion from a single B cell contained within a pen bound to capture beads at the mouth of the pen. In assay 1, antibody secretion was assessed by detection of total IgG in the FITC detection channel via binding of an anti-mouse IgG AF488 conjugated secondary and simultaneously the specificity for S1 protein was determined in the CY5 detection channel with AF647 conjugated S1 protein at 200 nM. In assay 2, binding competition between secreted antibody from the B cell and ACE2 receptor was assessed by precomplexing AF647 conjugated S1 protein with a molar excess of recombinant ACE2. A lack of antibody binding to S1 protein under these conditions demonstrated binding to a similar epitope as ACE2, thus indicative of a potential blocking candidate.